Turn off all menus for a screenshot
There are different ways to accomplish your goal, depending on your specific needs.

Viewport Render

The viewport can be rendered through View > Viewport Render Image.



Screenshot of the active area

A screenshot of the active area can be created using the following steps:


Hide the gizmos

Open the operator search F3 and search for Save Screenshot.
Run the Save Screenshot operator (bpy.ops.screen.screenshot()).
Uncheck the Full Screen property (this will only include the active area) and save the image.



Fullscreen mode &amp; third-party software

The following steps enabled the fullscreen mode and allow you to take a screenshot with a third-party tool:


Hide the gizmos

Switch to fullscreen mode through View > Area > Toggles Fullscreen Area (Ctrl+Alt+Space).
Use a third-party tool to create the screenshot
In order to leave the fullscreen mode move the mouse cursor to the upper right corner and click on the icon . Alternatively you can also press the shortcut again Ctrl+Alt+Space